mirror of
https://github.com/berkeleydb/libdb.git
synced 2024-11-17 01:26:25 +00:00
207 lines
7.4 KiB
HTML
207 lines
7.4 KiB
HTML
|
<?xml version="1.0" encoding="UTF-8" standalone="no"?>
|
|||
|
|
<!DOCTYPE html PUBLIC "-//W3C//DTD XHTML 1.0 Transitional//EN" "http://www.w3.org/TR/xhtml1/DTD/xhtml1-transitional.dtd">
|
|||
|
|
<html xmlns="http://www.w3.org/1999/xhtml">
|
|||
|
|
<head>
|
|||
|
|
<meta http-equiv="Content-Type" content="text/html; charset=UTF-8" />
|
|||
|
|
<title>Opening a Transactional Environment and Store or Database</title>
|
|||
|
|
<link rel="stylesheet" href="gettingStarted.css" type="text/css" />
|
|||
|
|
<meta name="generator" content="DocBook XSL Stylesheets V1.73.2" />
|
|||
|
|
<link rel="start" href="index.html" title="Getting Started with Berkeley DB Transaction Processing" />
|
|||
|
|
<link rel="up" href="enabletxn.html" title="Chapter 2. Enabling Transactions" />
|
|||
|
|
<link rel="prev" href="enabletxn.html" title="Chapter 2. Enabling Transactions" />
|
|||
|
|
<link rel="next" href="usingtxns.html" title="Chapter 3. Transaction Basics" />
|
|||
|
|
</head>
|
|||
|
|
<body>
|
|||
|
|
<div xmlns="" class="navheader">
|
|||
|
|
<div class="libver">
|
|||
|
|
<p>Library Version 11.2.5.2</p>
|
|||
|
|
</div>
|
|||
|
|
<table width="100%" summary="Navigation header">
|
|||
|
|
<tr>
|
|||
|
|
<th colspan="3" align="center">Opening a Transactional Environment and
|
|||
|
|
|
|||
|
|
<span xmlns="http://www.w3.org/1999/xhtml">Store or Database</span>
|
|||
|
|
|
|||
|
|
</th>
|
|||
|
|
</tr>
|
|||
|
|
<tr>
|
|||
|
|
<td width="20%" align="left"><a accesskey="p" href="enabletxn.html">Prev</a> </td>
|
|||
|
|
<th width="60%" align="center">Chapter 2. Enabling Transactions</th>
|
|||
|
|
<td width="20%" align="right"> <a accesskey="n" href="usingtxns.html">Next</a></td>
|
|||
|
|
</tr>
|
|||
|
|
</table>
|
|||
|
|
<hr />
|
|||
|
|
</div>
|
|||
|
|
<div class="sect1" lang="en" xml:lang="en">
|
|||
|
|
<div class="titlepage">
|
|||
|
|
<div>
|
|||
|
|
<div>
|
|||
|
|
<h2 class="title" style="clear: both"><a id="envopen"></a>Opening a Transactional Environment and
|
|||
|
|
|
|||
|
|
<span>Store or Database</span>
|
|||
|
|
|
|||
|
|
</h2>
|
|||
|
|
</div>
|
|||
|
|
</div>
|
|||
|
|
</div>
|
|||
|
|
<p>
|
|||
|
|
To enable transactions for your environment, you must initialize the
|
|||
|
|
transactional subsystem. Note that doing this also initializes the
|
|||
|
|
logging subsystem. In addition, you must initialize the memory pool
|
|||
|
|
(in-memory cache). You must also initialize the locking subsystem.
|
|||
|
|
|
|||
|
|
|
|||
|
|
|
|||
|
|
<span>
|
|||
|
|
For example, to do this with the DPL:
|
|||
|
|
</span>
|
|||
|
|
</p>
|
|||
|
|
<pre class="programlisting">package persist.txn;
|
|||
|
|
|
|||
|
|
import com.sleepycat.db.DatabaseException;
|
|||
|
|
import com.sleepycat.db.Environment;
|
|||
|
|
import com.sleepycat.db.EnvironmentConfig;
|
|||
|
|
|
|||
|
|
import com.sleepycat.persist.EntityStore;
|
|||
|
|
import com.sleepycat.persist.StoreConfig;
|
|||
|
|
|
|||
|
|
import java.io.File;
|
|||
|
|
import java.io.FileNotFoundException;
|
|||
|
|
|
|||
|
|
...
|
|||
|
|
|
|||
|
|
Environment myEnv = null;
|
|||
|
|
EntityStore myStore = null;
|
|||
|
|
try {
|
|||
|
|
EnvironmentConfig myEnvConfig = new EnvironmentConfig();
|
|||
|
|
StoreConfig storeConfig = new StoreConfig();
|
|||
|
|
|
|||
|
|
myEnvConfig.setInitializeCache(true);
|
|||
|
|
myEnvConfig.setInitializeLocking(true);
|
|||
|
|
myEnvConfig.setInitializeLogging(true);
|
|||
|
|
myEnvConfig.setTransactional(true);
|
|||
|
|
|
|||
|
|
storeConfig.setTransactional(true);
|
|||
|
|
|
|||
|
|
myEnv = new Environment(new File("/my/env/home"),
|
|||
|
|
myEnvConfig);
|
|||
|
|
|
|||
|
|
myStore = new EntityStore(myEnv, "EntityStore", storeConfig);
|
|||
|
|
|
|||
|
|
} catch (DatabaseException de) {
|
|||
|
|
// Exception handling goes here
|
|||
|
|
} catch (FileNotFoundException fnfe) {
|
|||
|
|
// Exception handling goes here
|
|||
|
|
}</pre>
|
|||
|
|
<p>
|
|||
|
|
And when using the base API:
|
|||
|
|
</p>
|
|||
|
|
<pre class="programlisting">package db.txn;
|
|||
|
|
|
|||
|
|
import com.sleepycat.db.DatabaseException;
|
|||
|
|
import com.sleepycat.db.Environment;
|
|||
|
|
import com.sleepycat.db.EnvironmentConfig;
|
|||
|
|
|
|||
|
|
import java.io.File;
|
|||
|
|
import java.io.FileNotFoundException;
|
|||
|
|
|
|||
|
|
...
|
|||
|
|
|
|||
|
|
Environment myEnv = null;
|
|||
|
|
try {
|
|||
|
|
EnvironmentConfig myEnvConfig = new EnvironmentConfig();
|
|||
|
|
myEnvConfig.setInitializeCache(true);
|
|||
|
|
myEnvConfig.setInitializeLocking(true);
|
|||
|
|
myEnvConfig.setInitializeLogging(true);
|
|||
|
|
myEnvConfig.setTransactional(true);
|
|||
|
|
|
|||
|
|
myEnv = new Environment(new File("/my/env/home"),
|
|||
|
|
myEnvConfig);
|
|||
|
|
|
|||
|
|
} catch (DatabaseException de) {
|
|||
|
|
// Exception handling goes here
|
|||
|
|
} catch (FileNotFoundException fnfe) {
|
|||
|
|
// Exception handling goes here
|
|||
|
|
}</pre>
|
|||
|
|
<p>
|
|||
|
|
You then can use the <code class="classname">Environment</code> handle to open
|
|||
|
|
your database(s) using <code class="methodname">Environment.openDatabase()</code>.
|
|||
|
|
Note that when you do this, you must set
|
|||
|
|
<code class="methodname">DatabaseConfig.setTransactional()</code>
|
|||
|
|
to <code class="literal">true</code>. Note that in effect this causes the
|
|||
|
|
database open to be transactional protected because it results in
|
|||
|
|
auto commit being used for the open (if a transaction is not explicitly
|
|||
|
|
used to protect the open).
|
|||
|
|
For example:
|
|||
|
|
</p>
|
|||
|
|
<pre class="programlisting">package db.txn;
|
|||
|
|
|
|||
|
|
<strong class="userinput"><code>import com.sleepycat.db.Database;
|
|||
|
|
import com.sleepycat.db.DatabaseType;
|
|||
|
|
import com.sleepycat.db.DatabaseConfig;</code></strong>
|
|||
|
|
import com.sleepycat.db.DatabaseException;
|
|||
|
|
import com.sleepycat.db.Environment;
|
|||
|
|
import com.sleepycat.db.EnvironmentConfig;
|
|||
|
|
|
|||
|
|
import java.io.File;
|
|||
|
|
import java.io.FileNotFoundException;
|
|||
|
|
|
|||
|
|
...
|
|||
|
|
|
|||
|
|
<strong class="userinput"><code>Database myDatabase = null;</code></strong>
|
|||
|
|
Environment myEnv = null;
|
|||
|
|
try {
|
|||
|
|
EnvironmentConfig myEnvConfig = new EnvironmentConfig();
|
|||
|
|
myEnvConfig.setInitializeCache(true);
|
|||
|
|
myEnvConfig.setInitializeLocking(true);
|
|||
|
|
myEnvConfig.setInitializeLogging(true);
|
|||
|
|
myEnvConfig.setTransactional(true);
|
|||
|
|
|
|||
|
|
myEnv = new Environment(new File("/my/env/home"),
|
|||
|
|
myEnvConfig);
|
|||
|
|
|
|||
|
|
<strong class="userinput"><code>// Open the database.
|
|||
|
|
DatabaseConfig dbConfig = new DatabaseConfig();
|
|||
|
|
dbConfig.setTransactional(true);
|
|||
|
|
dbConfig.setType(DatabaseType.BTREE);
|
|||
|
|
myDatabase = myEnv.openDatabase(null, // txn handle
|
|||
|
|
"sampleDatabase", // db file name
|
|||
|
|
null, // db name
|
|||
|
|
dbConfig);</code></strong>
|
|||
|
|
} catch (DatabaseException de) {
|
|||
|
|
// Exception handling goes here
|
|||
|
|
} catch (FileNotFoundException fnfe) {
|
|||
|
|
// Exception handling goes here
|
|||
|
|
}</pre>
|
|||
|
|
<div class="note" style="margin-left: 0.5in; margin-right: 0.5in;">
|
|||
|
|
<h3 class="title">Note</h3>
|
|||
|
|
<p>
|
|||
|
|
Never close a database <span> or
|
|||
|
|
store </span> that has active transactions. Make sure
|
|||
|
|
all transactions are resolved (either committed or aborted)
|
|||
|
|
before closing the database.
|
|||
|
|
</p>
|
|||
|
|
</div>
|
|||
|
|
</div>
|
|||
|
|
<div class="navfooter">
|
|||
|
|
<hr />
|
|||
|
|
<table width="100%" summary="Navigation footer">
|
|||
|
|
<tr>
|
|||
|
|
<td width="40%" align="left"><a accesskey="p" href="enabletxn.html">Prev</a> </td>
|
|||
|
|
<td width="20%" align="center">
|
|||
|
|
<a accesskey="u" href="enabletxn.html">Up</a>
|
|||
|
|
</td>
|
|||
|
|
<td width="40%" align="right"> <a accesskey="n" href="usingtxns.html">Next</a></td>
|
|||
|
|
</tr>
|
|||
|
|
<tr>
|
|||
|
|
<td width="40%" align="left" valign="top">Chapter 2. Enabling Transactions </td>
|
|||
|
|
<td width="20%" align="center">
|
|||
|
|
<a accesskey="h" href="index.html">Home</a>
|
|||
|
|
</td>
|
|||
|
|
<td width="40%" align="right" valign="top"> Chapter 3. Transaction Basics</td>
|
|||
|
|
</tr>
|
|||
|
|
</table>
|
|||
|
|
</div>
|
|||
|
|
</body>
|
|||
|
|
</html>
|